Recently completed an on-premises Exchange to Office 365 hosted Exchange cutover migration. Everything went as advertised and the company is using hosted Exchange without issues. The on-premises Exchange server has been shut down since the migration. The one issue I'm having: When someone sends an email from the company domain to one of the employees' PERSONAL bellsouth.net account, the bellsouth.net account holder gets the email, but then gets another email saying (see graphic): This sender failed our fraud detection checks and may not be who they appear to be. I reviewed the DNS records for the company domain and found a legacy SRV mail protection record and a mail A record related to the on-premises Exchange server, which I have since deleted. But even after a day or so allowing for propagation, the problem persists. Thoughts?